Screening apparatus



April 20, 1937. G. R. DELAMATER SCREENING APPARATUS Filed March 3, 19333 Sheets-Sheet 1 INVENTOR. 6 co r 6 fyZa me 76/ April 1937- G. R.DELAMATER 2,077,678

SCREENING APPARATUS Filed March s, 1935 3 Sheets-Sheet 2 INVENTOR.660796 A? Z7eZama7 /r BY ATTORNEYS April 20, 1937. G. R. DELAMATERSCREENING APPARATUS Filed March 3,- 1935 3 Sheets-Sheet 5 r 6 M M m I P.6 .9 A 73 68 6 however, but one of various ways in which the.

Patented Apr. 20, 1937 UNITED STATES SCREENING APPARATUS George R.Deiamater, Shaker Heights, Ohio, as-

signor to The W. S. Tyler Company, Cleveland, Ohio, a corporation ofOhio Application March 3, 1933, Serial No. 659,573

. 1 Claim.

The present improvements; relating as indicated to screening apparatus,are more particularly adapted to improved apparatus for screening orclassifying materials, although, as will be apparent from the followingdescription, the use of the present apparatus is not necessarily limitedto any particular type of material. One of the principal objects of theinvention is the provision of a simple and rugged apparatus foraccurately classifying bulk material, providing a close separation andhandling a large tonnage. A further object of the invention is theprovision of apparatus which will carry out the above purposes with aminimum of maintenance expense.

To the accomplishment of the foregoing and related ends, said invention,then, consists of the means hereinafter fully described and particularlypointed out in the claim; the annexed drawings and the followingdescription setting forth in detail certain means of carrying out theinvention, such disclosed means illustrating,

principle of the invention may be used.

In said annexed drawings:-

Fig. 1 is a view in perspective, partially sectioned, of one form of myimproved apparatus; Fig. 2 is a side elevation of one corner of theapparatus, showing one of the means for imparting movement to thescreening surface; Fig. 3 is a transverse'central section through one'of the vibrating means;'and Fig. 4 is a partial plan view, partially insection, of one comer of the apparatus showing the relation between theframe and one of the vibrating mechanism.

In the classifying of bulk materials the two generally employed methodsare the separation of material by air, which is ordinarily applied onlyto remove the extremely fine material from the coarse and vibrating,shaking or other types of screens for the separations which cannot behandled by air separation methods.

This apparatus employs woven wire cloth as the final separatinginstrument and provides for uniform ten'sioning of this cloth whichassures maximum screening eificiency and life of screen cloth. Provisionis also made to vibrate this cloth rapidly in a plane at an angle to theplane of the material passing thereover. Materials of almost anyreasonable size may be fed to this apparatus but its type of vibrationmakes it more suitable for vibrating screen cloth not exceeding 1%"clear opening.

In the present apparatus I have developed a simple and rugged mechanismfor the handling of coarse material in which a frame carrying a sectionof taut woven-wire screen is vibrated uniformly throughout its area bysimple and rugged mechanism disposed preferably at the corners of therectangular frame, the mechanism being also provided with means foraccentuating or increasing the movement given to the frame by thevibrating mechanism. In Fig. 1 I have shown a view in perspective of oneform. of my improved apparatus consisting of a supporting frame composedof I-beams I and 2, which are rigidly secured together to form arectangular enclosure which is mounted upon any suitable supports in aninclined position, as shown in Fig. 1. The mounting or base for therigid frame may of course take various forms and may be provided, as iscommon in such apparatus, with means for adjusting the inclination ofthe frame for various purposes. Mounted within the outlines of the base,but above the screen, is a second and separate rectangular frameconsisting of end members 3 and side angles 4, which are rigidly securedtogether and provide the frame on which the woven wire screen or screenbar or rods are mounted. Mounted longitudinally and equidistantly fromthe side channels 4 are anglemembers 5 and 6 which are rigidly securedto the end members 3 of the movable frame and which act to stiffen thisframe and to provide raised members, over which the screen cloth I maybe stretched to give the latter a curved or arched upper surface. Tofurther insure complete rigidity, the longitudinal angles 4 of themovable frame are reinforced by truss members H! extending from end toend of each angle. The movable frame is further stiffened by means oftransverse members 9 mounted below the plane of the screen so that themovable frame is an extremely rigid, rectangular member for supportingthe screen in a predetermined condition as regards the contour of theupper surface and the tension.

Since the screen-receiving frame Just described is mounted in aninclined position and is freely supported between springs acting at anangle to the plane of the screen, as will presently be described, itwill be desirable to anchor the frame in a predetermined position withrespect to the base,. the supporting springs to be described and thevibrating means. For this purpose I employ members l5, which of fiatstrip elements which are fixed in spaced brackets l6 intermediate theends of the frame and which, at their ends, are attached to U-bolts 50engaged with channel members 18 which are secured to the ends of thescreen-receiving frame.

These guide members i5 serve the double purpose of maintaining the framein the desired position with respect to the base, the supporting springsand the vibrating mechanism and absorb all end thrust which mightotherwise be directed onto some part of the vibrating mechanism or thespring supports.

The extending portions i8 of the transverse frame members 3 are securedto the armature 20 of an electromagnetic device which is mounted arehere shown in the form upon a coil spring it supported upon a suitableplate 22 carried in an enclosing housing 23, one of which is'mounted ateach corner of the entire frame. The armature 2G is actuated by anelectro-magnet 26 mounted in the upper portion of the housing 23, whereit is appropriately secured. Mounted in an extension housing 3t securedin the main housing 23 is a spring 25, which engages against the top ofthe frame end iii, causing this frame end and the entire movable frameto be fioatingly supported between the springs 2i and 25. The latterspring may be adjusted as to its tension by means of an adjusting bolt26 and thrust plate 2?, adjustment being had by removing the top orcover 28 of the extension housing.

The woven wire screen i is provided with a reinforced rebent edgeportion adapted to be secured by hook bolts 36, which are carried in thelongitudinal side members i of the movable frame where they areadjustably secured by means of nuts bl. By loosening the nuts 37, thebolts may be moved inwardly toward the center of the movable frame asumcient distance to permit the rebent hooked edges of the screen i tobe caught, after which the bolts can be tightened to bring the entirewoven Wire screen into any desired tension and into a curved conditionover the supporting members 5 and t in the central portion of the frame.A guard 39 is pivotally mounted about a longitudinally extending rod Micarried upon suitable posts extending upwardly from the longitudinalmembers l of the inner frame, and this guard may be swung upwardly aboutits axis to permit of removal of the screen and is provided with aninwardly curved lower edge ill adapted to fit between the book ends ofthe bolts as and the curved edge strip of the screen so that tensioningof the bolts locks the guard member into the position shown in Fig. 1,and the latter prevents the leakage of any material through the side ofthe frame. The bolts, guard and edge portion of the screen are soproportioned that tensioning of the bolts tightens the reinforced edgeportion of the screen against the horizontal flange d2 of the angle.

4 adjusting the tension of the spring 25, but regardless of thisadjustment the mounting of the entire frame is made resilient and livelyand the movement thus imparted to it permits a relative ly small currentconsumption to provide a rapid, lively and, if desired, wide amplitudeof movement for the screen frame which produces a sharp separation and amarked increase in tonnage over machines heretofore used in thescreening of coarse materials. By this mechanism all portions of thescreen surface are in precisely the same degree of tension and are giventhe same degree of movement, which has never been the case with priorapparatus commonly used for the classifying of coarse material, and thisaccounts partially for the increase in the capacity and also for theincrease'in the accuracy of the separation.

While I have referred above to the. fact that it is possible, ifdesired, to impart a considerable amplitude of movement to the entirescreen, it

aoraere will be evident that one of the chief distinctions of thepresent apparatus over prior mechanically operated screening apparatusis that a very much shorter amplitude of motion imparted to the screensurface will have a greater effect than in prior machines. In anymachine in which vibration is imparted directly to the screen surfaceeither at the center of the screen or along the center line of thescreen which is stretched between any two spaced edges, the amplitude atthe point of connection of the vibration-imparting apparatus has to begreater than is really desirable in order to produce an approximation ofthe desired amplitude at points spaced from the point of connection. Inone type of screening apparatus in which one or more electro-magnets aresecured to the screen along a central line a screening action is securedwhich has been superior in the screening of fine materials to thatobtainable by any other apparatus, but

even this machine has represented a compromise in that an excessiveamplitude of movement had to be imparted to the center of the screen. inorder to secure the desired amplitude between the central part and theedges. It is of course impossible in such an apparatus to secure thesame amplitude all over the surface, and the edge portions aresubstantially unvibrated and represent dead areas so far as activescreening is concerned.

The present apparatus for the first time presents a machine for thescreening of fine materials in which the entire screen surface is intension and therefore equally effective and equally resistant to wear,and in which a rapid electro= 7 magnetic vibration can be imparted tothe entire screening area instead of the slower mechanical vibrationimparted by unbalanced weights, cranks cams and. similar devices.Furthermore, exactly the desired strolre can be given to the screen andthis amplitude will be uniform all over the screen surface. Thisinevitably increases the tonnage and the accuracy of the separation,while the movement of the entire screen and screen frame at an angle tothe plane of the screen allows a lower screening angle, again tending toincrease the tonnage, and acts to feed the material over the screensurface. The lower the screen angle and the shorter the amplitude ofmovement, the more continuous the contact between the material and. thescreen and the greater the opportunity for the particles to pass throughthe meshes of the screen, which of course tends to increase the capacityand the accuracy.

Other'modes of applying the principle of my invention may be employedinstead of the one explained, change being made as regards the meansherein disclosed, provided those stated by the following claim or itsequivalent be employed.

1 therefore particularly point out and distinctly claim as myinvention:-

In a screening apparatus the combination of a I. base, a rigid framemounted in an inclined position, resilient supporting means mountedbetween said base and frame, and resilient cushioning means above saidframe, said frame being rectangular, thus providing corners, there beingelectrc-magnetic vibrating means mounted at each corner, said framebeing maintained in superposed position with respect to said base bymeans of resilient anchoring elements connected to the central portionof said base and to the opposite ends of said frame.

- GEORGE R. DELAMATER.

